18 years old 5 weeks pregnant.. Help !

I’m 18 years old and 5 weeks pregnant .. I need advice because my grandmother keeps tellin me that my relationship is not going to last with the father of my unborn baby.. It’s very early still , yes I know but they don’t know him like I know him and he is fully committed and willing do step up and do his duties but yet again my grandmother doesn’t want me to keep it she says I have a whole future ahead and I’m messing up my life .. I know what I gotta to and what I have to get done .. I want my baby , yes, but I’m still kind of confuse because she keeps repeating the same thing over and over I need advice or anyone that can relate … Thank you ❤️